Is it a violation of RFC (and BCP) 2505?

[Chin Fang]

I got the following bounce today:

   From rereg at qatestsession1.qa.netsol.com Fri Sep 01 08:51:24 2000
   Return-Path: <rereg at qatestsession1.qa.netsol.com>
   .....
   Received: (from rereg at localhost)
           by qatestsession1.qa.netsol.com (8.8.8+Sun/8.8.8) id EAA10916;
           Fri, 1 Sep 2000 04:48:27 -0400 (EDT)
   Date: Fri, 1 Sep 2000 04:48:27 -0400 (EDT)
   Message-Id: <200009010848.EAA10916 at qatestsession1.qa.netsol.com>
   Reply-To: hostmaster at networksolutions.com
   From: thedotcompeople at qatestsession1.qa.netsol.com
   [.... rest removed ...]

So, it's a domain name application.  Feeling curious, I did a nslookup
on qatestsession1.qa.netsol.com, immediately got the "Non-existent
host/domain" error.

The fact that the lowest Received: line shows the host indicates to me
that the host is resolvable via internal name servers inside of NSI,
but the hostname is not announced in NSI's external name servers.

However, if my understanding of the following from RFC 2505 is correct:

2.9. Verify "MAIL From:"

   The MTA SHOULD be able to perform a simple "sanity check" of the
   "MAIL From:" domain and refuse to receive mail if that domain is
   nonexistent (i.e. does not resolve to having an MX or an A record).
   If the DNS error is temporary, TempFail, the MTA MUST return a 4xx
   Return Code (Temporary Error). If the DNS error is an Authoritative
   NXdomain (host/domain unknown) the MTA SHOULD still return a 4xx
   Return Code (since this may just be primary and secondary DNS not
   being in sync) but it MAY allow for an 5xx Return Code (as configured
   by the sysadmin).

then by not making the hostname available for A or MX record checking,
Network Solutions, Inc. is foiling other people anti-spam effort, and
causing more administrative burden to administrators at other sites.

I would like to listen to others comments.  

Regards,

Chin Fang
fangchin at leland.stanford.edu